Several machines have been designed to apply seals and labels around bottles and other containers. One approach is to use shrinkable plastic material around the container, heated to shrink into position. Another is to expand a tubular plastic sleeve as it is placed over the container and then cut and released into position on the container as the material returns to its rest form.
Heat shrinkable materials are not useful as rings that require strength of a handle. Expandable film stock is also not suitable as a handle. A ring with substantial toroidal dimensions is generally required around the container, typically the bottle neck, to support a handle connected to the ring capable of lifting a filled container. But the toroidal ring with more physical strength of material also has more resistance to expansion than a band or label. A mechanical advantage is required in a machine that can reliably apply such rings over bottle necks in a rapid pace of a production line.